Robert J. Samuelson: Fearsome mega-trends

"There is no parallel in history to the (American) experiment of free government on this scale. The scale accounts for a great deal, including ... pessimism about the present or the future of America."

— Scottish historian D.W. Brogan in "The American Character," 1944

Just why is American politics so dysfunctional? One answer is that both parties, for different reasons, have created self-serving mythologies that reward them for not dealing with pressing problems that, though daunting, are hardly sudden or secret. For proof, see Paul Taylor's new book "The Next America." Taylor oversees the Pew Research Center's opinion surveys. His masterful synthesis of polls shows that three familiar mega-trends lie at the core of America's political and social stalemate.

First, immigration. By 2050, immigrants and their U.S.-born children are projected to represent 37 percent of the population, slightly higher than in 1900 when the country last experienced mass immigration. Between now and midcentury, immigrants and their children will generate two-thirds of population growth.

Second, family breakdown. In 2011, unmarried women accounted for 41 percent of U.S. births, up from 5 percent in 1960. The trend affects all major groups. The rate is 29 percent for whites, 53 percent among Hispanics and 72 percent among African-Americans. Although 60 percent of single mothers have live-in boyfriends, half of these relationships end within five years. Single parenthood's stigma is gone.

This may shape the future middle class because growing up in a single-parent home puts children at a disadvantage. Children in two-parent homes — despite millions of exceptions — are "healthier, do better academically, (and) get into less trouble as adolescents," writes Taylor, summarizing social-science research.

Finally, aging. Every day 10,000 baby boomers turn 65. The retiree flood tide is swamping the federal budget. By 2022, Social Security, Medicare and the non-child share of Medicaid will exceed half the budget, up from 30 percent in 1990, projects an Urban Institute study. To make room for the elderly, defense and many domestic programs are being relentlessly squeezed.

There's no generational justice, argues Taylor: "The young today are paying taxes to support a level of benefits for the old that they themselves have no prospect of receiving when they become old."

America's future rests heavily on how these mega-trends play out. Democracy works best when the political system can mediate between the often-inconsistent demands of public opinion and larger national needs. This, America's leaders can't or won't do. Faced with immutable trends, they have not adapted to change. Instead, they pander to partisans with soothing, though outdated, stereotypes. Nostalgia poses as policy when it is actually a marketing strategy.

Liberals won't come to terms with aging. Believing that spending on the elderly and near-elderly constitutes the essence of progressivism — and ignoring the affluence of many elderly — some liberals even support raising these benefits. The paradoxical result is that the pro-government party has become an instrument of anti-government policies, because accommodating all the elderly's benefits means quietly condoning deep cuts in most other programs.

By its nature, this brand of liberalism discriminates against the young. To be sure, their economic problems stem heavily from the Great Recession (in 2012, 40 percent of men ages 18 to 31 lived with their parents). But shrinking government services and looming tax increases compound the damage.

Conservatives have parallel hang-ups. They can't adapt to the permanence of Big Government or the presence of so many immigrants, including an estimated 11 million who are here illegally. Even if unworthy government programs are cut, federal spending will easily exceed one-fifth of national income, which is more than today's taxes will cover. Higher taxes, contrary to GOP dogma, will be needed. Similarly, undocumented immigrants won't conveniently vanish.

Government can't do much about the decline in marriage. But it isn't handcuffed elsewhere. What's needed is a bargain in which Democrats trim retiree benefits (Social Security, Medicare) and, in exchange, Republicans deal forthrightly on immigration and taxes. This seems unlikely, because it would require both parties to accept the world as it is, not as they wish it.

Appraising America's democratic prospects in the mid-1940s, historian Brogan wrote that "the pessimists have always been wrong." Maybe, but they're looking prescient now.